Consolidate bubble border code.

ui/app_list/app_list_background.h

+// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef UI_APP_LIST_APP_LIST_BACKGROUND_H_
+#define UI_APP_LIST_APP_LIST_BACKGROUND_H_
+
+#include "base/basictypes.h"
+#include "base/compiler_specific.h"
+#include "ui/views/background.h"
+
+namespace views {
+class View;
+}
+
+namespace app_list {
+
+// A class to paint bubble background.
+class AppListBackground : public views::Background {
+ public:
+  AppListBackground(int corner_radius,
+                    views::View* search_box_view);
+  virtual ~AppListBackground();
+
+ private:
+  // views::Background overrides:
+  virtual void Paint(gfx::Canvas* canvas, views::View* view) const OVERRIDE;
+
+  const int corner_radius_;
+  const views::View* search_box_view_;  // Owned by views hierarchy.
+
+  DISALLOW_COPY_AND_ASSIGN(AppListBackground);
+};
+
+}  // namespace app_list
+
+#endif  // UI_APP_LIST_APP_LIST_BACKGROUND_H_